<template>
  <!-- 分类页面 -->
  <view>
    <!-- //调用搜索组件 -->
    <!-- props传参可以动态绑定颜色 -->
    <my-search :bgColor="'#C00000'" @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧滚动区域 -->
        <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}" >
          <block v-for="(item,i) in cateList" :key="i">
            <view :class="['left-scroll-view-item',i === active ? 'active':'' ]" @click="activeChanged(i)">{{item.cat_name}}</view>
          </block>
        </scroll-view>
      <!-- 右侧滚动区域 -->
       <scroll-view class="right-scroll-view" scroll-y="true" :style="{height: wh + 'px'}":scroll-top="scrollTop">
         <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
           <view  class="cate-lv2-title">/ {{item2.cat_name}} /</view>
           <!-- 动态渲染三级列表分类 -->
           <view class="cate-lv3-list">
              <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                <image :src="item3.cat_icon"></image>
                <text>{{item3.cat_name}}</text>
              </view>
           </view>
         </view>
       </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  
  export default {
     mixins: [badgeMix],
    data() {
      return {
        //高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
        wh :0,
        //分类列表数据
         cateList: [],
         //选中当前索引
         active: 0,
         //二级分类标题列表
          cateLevel2: [],
          //解决切换左侧滚动条不在最顶上的问题 
          // 滚动条距离顶部的距离
          scrollTop:0
      };
    },
    onLoad() {  
      //调用获取分类列表数据
       this.getCateList()
      //获取当前系统信息
       const sysInfo = uni.getSystemInfoSync()
       //给wh动态赋值
       this.wh=sysInfo.windowHeight   
    }, 
    methods:{
      //获取分类数据的方法
       async getCateList() {
            const { data: res } = await uni.$http.get('/api/public/v1/categories')
            if (res.meta.status !== 200) return uni.$showMsg()
            this.cateList = res.message
            //为右侧的二级分类 标题赋值 获得右侧列表数据
            this.cateLevel2 = res.message[0].children
          },
          activeChanged(i){
            this.active = i
            //左侧改变 右侧也改变
            this.cateLevel2 = this.cateList[i].children
            
            // 改变scrollTop数值
            this.scrollTop = this.scrollTop ? 0:1
          },
          //点击三级分类 跳转商品列表
          gotoGoodsList(item3) {
            uni.navigateTo({
              url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
            })
          },
         gotoSearch(){
           // console.log('ok')
           uni.navigateTo({
             url: '/subpkg/search/search'
           })
         }
    }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  // 装不下自动换行
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    // 纵横居中
    flex-direction: column;
    justify-content: center;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
</style>
